[Dark Mode] Improve visual contrast of the ProgressBar control in dark mode.

[Zheng-Li01]

.NET version

9.0.0-rc.1.24414.1 + build private dll form winforms repo main branch

Did it work in .NET Framework?

No

Did it work in any of the earlier releases of .NET Core or .NET 5+?

This is a new feature Dark Mode: #11857

Issue description

The rest of part for ProgressBar control is invisible on DarkMode

Steps to reproduce

1. Create a WinForms .NET Core application with ProgressBar control.
2. Enable DarkMode by Application.SetColorMode(SystemColorMode.Dark) in Program.cs file.
3. Set the Value as "78"
4. Run the application.

[KlausLoeffelmann]

This is something that VisualStylesMode should address in .NET 10. Maybe we can also check contrast of used colors, although I think there is a bit more visual guidance necessary.

[dotnet-policy-service]

This issue is now marked as "help wanted", and we’re looking for a community volunteer to work on this issue. If we receive no interest in 180 days, we will close the issue. To learn more about how we handle feature requests, please see our documentation.

Happy Coding!